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Aim: The Visual Disability Assessment (VDA), a questionnaire for measuring the impact of cataract on visual functioning, was developed using classical test theory. Since this approach is limited, our aim was to further investigate the psychometric properties of the VDA using Rasch analysis.
Methods: 613 patients from the Flinders Medical Centre cataract surgery self-administered the VDA. Psychometric properties investigated for the overall VDA and each subscale included: measurement of a single construct (unidimensionality), item fit to the construct, reliable discrimination between strata of patient ability (person separation) and targeting of item difficulty to person ability.
Results: The VDA discriminated five strata of patient ability. However, seven mobility items constituted a second dimension and formed a valid separate scale. Sequestration of these items resulted in a unidimensional 11-item measure of activity limitation. Both the mobility and activity limitation scales had acceptable person separation and neither contained misfitting items. Targeting was suboptimal for mobility (-2.12 logits) but good for activity limitation (-0.72). The subscales also satisfied the requirements of the Rasch measurement model.
Conclusions: The Rasch-scaled VDA effectively measures two separate constructs: mobility and activity limitation (with two subscales). Its good psychometric properties make it suitable for measuring cataract surgery outcomes.
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http://dx.doi.org/10.1136/bjo.2009.169490 | DOI Listing |
Appl Radiat Isot
September 2025
Nuclear Engineering Department, School of Mechanical Engineering, Shiraz University, Shiraz, Iran.
Accurate determination of the parameters of each high purity germanium, HPGe detectors ensure the precision of quantitative results obtained from spectrum analysis. This study presents a comprehensive performance evaluation and long-term quality control assessment of a high-purity germanium (HPGe) gamma spectrometry system that has been operational for over 15 years. Key spectrometric measures were recorded, including energy resolution, peak shape ratios, asymmetry, peak-to-Compton ratio, relative efficiency, electronic noise, minimum detectable activity (MDA), and repeatability and reproducibility of the system.
View Article and Find Full Text PDFJ Trace Elem Med Biol
September 2025
Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, Kraków 31-343, Poland. Electronic address:
Vanadium (V) is a trace element in the environment; it is detected in soil, water, air, dust, and food products. V-containing compounds have shown therapeutic potential in the treatment of diabetes. However, studies on the effects of V on animal behavior remain limited and sporadic.
View Article and Find Full Text PDFArch Gerontol Geriatr
August 2025
School of Nursing, Jilin University, Changchun, China. Electronic address:
Background: Frailty is defined as a biological syndrome characterized by a decreased reserve and resistance to stressors. Frailty is closely related to lifestyle, and improving lifestyle can effectively reduce the incidence of frailty and related adverse events. Multi-component interventions were an effective mean of improving lifestyle, which has been validated in studies of other populations.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
National Engineering Research Center of Lower-Carbon Catalysis Technology, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
Zeolite-confined Rh-based catalysts have emerged as promising heterogeneous candidates for olefin hydroformylation. However, they face challenges of reactant- and product-induced Rh leaching and aggregation. Herein, zeolite framework-anchored Rh-(O-Zn) sites were designed and are shown to have remarkable activity and stability for gas-phase ethylene hydroformylation.
View Article and Find Full Text PDFJMIR Hum Factors
September 2025
Villa Beretta Rehabilitation Center, Costa Masnaga, Italy.
Background: Telerehabilitation is a promising solution to provide continuity of care. Most existing telerehabilitation platforms focus on rehabilitating upper limbs, balance, and cognitive training, but exercises improving cardiovascular fitness are often neglected.
Objective: The objective of this study is to evaluate the acceptability and feasibility of a telerehabilitation intervention combining cognitive and aerobic exercises.